MEA based nonlinearity correction algorithm for the VCO of LFMCW radar level gauge

In this paper, Mind Evolutionary Algorithm (MEA) is introduced to correct the nonlinearity of voltage-controlled oscillator (VCO) in linear frequency modulation continuous wave (LFMCW) radar level gauge. Firstly, the frequency modulation (FM) voltage is divided into several subsections. By using fast Fourier transform (FFT) analysis for the beat frequency signals and distilling the characteristic of the spectrum, an evaluation function is constructed. Then MEA is applied to optimize the end coordinates of the subsections to achieve the nonlinear curve of FM voltage so as to compensate for the nonlinearity of VCO. Experiments show that the proposed method has good correction performance with no requirement of additional hardware and measuring equipment and is easy to apply.